Determination of the speed / banwidth for fast photodetectors using picosecond lasers

Abstract

The paper contains a survey of the problems commonly encountered by anyone attempting to accurately determine or specify the speed of fast photodetectors, in the bandwidth range: hundreds of MHz - tens of GHz. Two techniques are presented: one determining the minimum duration of the optical pulses which can be "seen" accurately enough, and the other determining the electrical (power) spectrum of the photodetector, leading to bandwidth determination. Experimental determination of the bandwidth for two fast photodiodes is presented, using the latter technique.